I really need/want to flash TWRP, but every single time I do it (via Heimdall), no matter what I do, I always get Cyanogen Recovery, which is completely useless, back over it when I boot into recovery mode. I tried shutting the phone off after flashing and booting directly into recovery mode as some people suggested, but it makes no difference. Yes, I've turned off the option in developer options to update cyanogen recovery, but 12.1 ignores that setting anyways and rewrites any custom recoveries anyways.

Does anyone know how I can get rid of cm recovery and replace it with TWRP? I would be extremely thankful.